Supplemental Prospectus (Form 424B3)

Filed Pursuant to Rule 424(b)(3)

Registration No. 333-284501

PROSPECTUS SUPPLEMENT NO. 9

(To prospectus dated March 7, 2025)

Primo Brands Corporation

This prospectus supplement updates, amends, and supplements the prospectus dated March 7, 2025 (the "Prospectus"), which forms a part of our Registration Statement on Form S-1, as amended (Registration No. 333-284501).

This prospectus supplement is being filed to update, amend, and supplement the information included in the Prospectus with the information contained in our Current Report on Form 8-K filed with the Securities and Exchange Commission (the "SEC") on September 12, 2025, which is set forth below.

This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunction with the Prospectus, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to the extent that the information in this prospectus supplement updates or supersedes the information contained in the Prospectus. Capitalized terms used in this prospectus supplement and not otherwise defined herein have the meanings specified in the Prospectus. Please keep this prospectus supplement with your Prospectus for future reference.

Our Class A common stock is listed on the New York Stock Exchange ("NYSE") under the symbol "PRMB." On September 11, 2025, the closing price of our Class A common stock on the NYSE was $24.32.

Investing in our securities involves certain risks. See the section entitled "Risk Factors" beginning on page 6 of the Prospectus and under similar headings in any further amendments or supplements to the Prospectus to read about factors you should consider before buying our securities.

Neither the SEC nor any state securities commission nor any other regulatory body has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus supplement or the Prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus supplement is September 12, 2025.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 9, 2025

Primo Brands Corporation

(Exact name of registrant as specified in its charter)

(Address of principal executive offices, including zip code)

Registrant's telephone number, including area code: (813) 544-8515

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

On September 9, 2025, Primo Brands Corporation (the "Company") determined that, in connection with a planned leave of absence, Robert Austin would temporarily cease to serve as Chief Operating Officer of the Company, effective September 30, 2025. During this time, Mr. Austin will serve as a Senior Advisor to the Company.

On September 10, 2025, the Company's Board of Directors designated the Company's Chief Executive Officer, Robbert Rietbroek, to serve as the Company's principal operating officer during the interim period until Mr. Austin's return, during which time certain senior operations executives will report directly to Mr. Rietbroek. Mr. Rietbroek's biographical information can be found in the Company's definitive proxy statement filed with the Securities and Exchange Commission on March 20, 2025, which is incorporated herein by reference.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.